How an argument with Hawking suggested the Universe is a hologram

Stephen Hawking had a hard time accepting that the event horizon of a black …

The proponents of string theory seem to think they can provide a more elegant description of the Universe by adding additional dimensions. But some other theoreticians think they've found a way to view the Universe as having one less dimension. The work sprung out of a long argument with Stephen Hawking about the nature of black holes, which was eventually solved by the realization that the event horizon could act as a hologram, preserving information about the material that's gotten sucked inside. The same sort of math, it turns out, can actually describe any point in the Universe, meaning that the entire content Universe can be viewed as a giant hologram, one that resides on the surface of whatever two-dimensional shape will enclose it.

That was the premise of panel at this summer's World Science Festival, which described how the idea developed, how it might apply to the Universe as a whole, and how they were involved in its development.

The whole argument started when Stephen Hawking attempted to describe what happens to matter during its lifetime in a black hole. He suggested that, from the perspective of quantum mechanics, the information about the quantum state of a particle that enters a black hole goes with it. This isn't a problem until the black hole starts to boil away through what's now called Hawking radiation, which creates a separate particle outside the event horizon while destroying one inside. This process ensures that the matter that escapes the black hole has no connection to the quantum state of the material that had gotten sucked in. As a result, information is destroyed. And that causes a problem, as the panel described.

As far as quantum mechanics is concerned, information about states is never destroyed. This isn't just an observation; according to panelist Leonard Susskind, destroying information creates paradoxes that, although apparently minor, will gradually propagate and eventually cause inconsistencies in just about everything we think we understand. As panelist Leonard Susskind put it, "all we know about physics would fall apart if information is lost."

Unfortunately, that's precisely what Hawking suggested was happening. "Hawking used quantum theory to derive a result that was at odds with quantum theory," as Nobel Laureate Gerard 't Hooft described the situation. Still, that wasn't all bad; it created a paradox and "Paradoxes make physicists happy."

"It was very hard to see what was wrong with what he was saying," Susskind said, "and even harder to get Hawking to see what was wrong."

The arguments apparently got very heated. Herman Verlinde, another physicist on the panel, described how there would often be silences when it was clear that Hawking had some thoughts on whatever was under discussion; these often ended when Hawking said "rubbish." "When Hawking says 'rubbish,'" he said, "you've lost the argument."

't Hooft described how the disagreement eventually got worked out. It's possible, he said, to figure out how much information has gotten drawn in to the black hole. Once you do that, you can see that the total amount can be related to the surface area of the event horizon, which suggested where the information could be stored. But since the event horizon is a two-dimensional surface, the information couldn't be stored in regular matter; instead, the event horizon forms a hologram that holds the information as matter passes through it. When that matter passes back out as Hawking radiation, the information is restored.

Susskind described just how counterintuitive this is. The holograms we're familiar with store an interference pattern that only becomes information we can interpret once light passes through them. On a micro-scale, related bits of information may be scattered far apart, and it's impossible to figure out what bit encodes what. And, when it comes to the event horizon, the bits are vanishingly small, on the level of the Planck scale (1.6 x 10-35 meters). These bits are so small, as 't Hooft noted, that you can store a staggering amount of information in a reasonable amount of space—enough to describe all the information that's been sucked into a black hole.

The price, as Susskind noted, was that the information is "hopelessly scrambled" when you do so.

From a black hole to the Universe

Berkeley's Raphael Bousso was on hand to describe how these ideas were expanded out to encompass the Universe as a whole. As he put it, the math that describes how much information a surface can store works just as well if you get rid of the black hole and event horizon. (This shouldn't be a huge surprise, given that most of the Universe is far less dense than the area inside a black hole.) Any surface that encloses an area of space in this Universe has sufficient capacity to describe its contents. The math, he said, works so well that "it seems like a conspiracy."

To him, at least. Verlinde pointed out that things in the Universe scale with volume, so it's counterintuitive that we should expect its representation to them to scale with a surface area. That counterintuitiveness, he thinks, is one of the reasons that the idea has had a hard time being accepted by many.

When it comes to the basic idea—the Universe can be described using a hologram—the panel was pretty much uniform, and Susskind clearly felt there was a consensus in its favor. But, he noted, as soon as you stepped beyond the basics, everybody had their own ideas, and those started coming out as the panel went along. Bousso, for example, felt that the holographic principle was "your ticket to quantum gravity." Objects are all attracted via gravity in the same way, he said, and the holographic principle might provide an avenue for understanding why (if he had an idea about how, though, he didn't share it with the audience). Verlinde seemed to agree, suggesting that, when you get to objects that are close to the Planck scale, gravity is simply an emergent property.

But 't Hooft seemed to be hoping that the holographic principle could solve a lot more than the quantum nature of gravity—to him, it suggested there might be something underlying quantum mechanics. For him, the holographic principle was a bit of an enigma, since disturbances happen in three dimensions, but propagate to a scrambled two-dimensional representation, all while obeying the Universe's speed limit (that of light). For him, this suggests there's something underneath it all, and he'd like to see it be something that's a bit more causal than the probabilistic world of quantum mechanics; he's hoping that a deterministic world exists somewhere near the Planck scale. Nobody else on the panel seemed to be all that excited about the prospect, though.

What was missing from the discussion was an attempt to tackle one of the issues that plagues string theory: the math may all work out and it could provide a convenient way of looking at the world, but is it actually related to anything in the actual, physical Universe? Nobody even attempted to tackle that question. Still, the panel did a good job of describing how something that started as an attempt to handle a special case—the loss of matter into a black hole—could provide a new way of looking at the Universe. And, in the process, how people could eventually convince Stephen Hawking he got one wrong.

The guy who thought of it.... (I forgot his name) Or purposefully repressed it because he is such an ass!!

So first off, this is not science, it is wild speculative nonsense.

Also, what is all the mystery surrounding black holes?

I believe part of this 'hologram' theory was an answer to the information paradox, you guessed it, another theory not based on any actual facts. So that makes holographic theory a theory based on no facts based on a theory that is also completely speculative that belongs in the pure maths realm.

I don't know how this crap is allowed air time. I actually saw the guy say " I walked passed a hologram one time and thought, I wonder if the universe is like that" ... then went to his desk, made some silly equation up then comes across as the most unbelievable asshole talking assertively that "you can't understand this theory because I don't even understand it" ..... You know what? Why don't you just go work at burger king, because you and the staff there would be on the same level.

Lets see.... A black hole, what is it? It is just a crushed core of a star, the things that are everywhere. More common than grains of sand on earth. In fact, it is so crushed that it creates a very dense concentration of matter, and as we all know mass distorts space time etc. So basically we have people babbling all kinds of rubbish about a really heavy bowling ball floating about in space. What is so freaking mysterious about that? It has immense gravity so nothing escapes. Its just like more mass falling to the surface of a planet, only its really really small and has gravity something like 4,000,000 times that of earths. There is no hole!!! Its just an object. The hole I believe refers to 4D gravimetric distortion effect of space. But in 3D, its just a bowling ball. Also, Mr Hawking, the information is not lost or destroyed, its still there. Its just a little flatter. When mass, photons, or anything is on the surface of a neutron star or 'black hole' it stays there until it is either ejected or removed by quantum mechanical effects. Maybe even hawking radiation. (which was his god damned theory in the first place) !!

So the whole universe could be enclosed within a two dimensional surface that holds the information about the universe on it's surface, albeit hopelessly scrambled? But the universe still exists, right? Or what would there be to encode? Is this just a useful way to think about the universe and "do the maths" or is this posited as an actuality, a la the black hole?

It has immense gravity so nothing escapes. Its just like more mass falling to the surface of a planet, only its really really small and has gravity something like 4,000,000 times that of earths. There is no hole!!! Its just an object.

Well, you sure are vehement, albeit arrogant and confused. The "hole" refers to the concept that stuff can go in, but can't come out. Yes, yes, modern nuances. But it was named a long time ago. Also, FYI, "shock absorbers" are actually spring dampeners. I guess car mechanics are all idiots too, for using the "wrong" terminology?

When mass, photons, or anything is on the surface of a neutron star or 'black hole' it stays there until it is either ejected or removed by quantum mechanical effects. Maybe even hawking radiation.

But if we can't get at the information in any way, isn't it lost?That said, a lot of what you're complaining about feels more like semantics than actual issue with the theories involved, you need to sort that out first. You go from "There is no hole!" to "The hole I believe refers to..." within two sentences.

Well, you sure are vehement, albeit arrogant and confused. The "hole" refers to the concept that stuff can go in, but can't come out. Yes, yes, modern nuances. But it was named a long time ago. Also, FYI, "shock absorbers" are actually spring dampeners. I guess car mechanics are all idiots too, for using the "wrong" terminology?

Hum, well I know nothing about cars and I'll admit, no one knows anything about space really. But According to a little known Albert Einstein an object, if its an atom or a planet, maybe even a star bends space around it. A little like displacement. This was proven a while back whilst observing the light from distant stars during a solar eclipse etc, etc. Gravitational Lensing.

Anyhooo. This distortion effect is also responsible for orbits of planets and galaxies and well, most things. But more importantly 'black holes' You see, in Einstein's theories a blackhole is kind of a mistake which leads to an object of infinite density and an infinitesimal size, this creates such a violent distortion of space that it could be described as a hole. A long bottomless infinite pit where things fall for, if not ever a very long time.

If you know anything about anything you will know that when an infinity is reached in a mathematical equation, it is otherwise known as wrong. Yes, Einstein was clever, but he didn't have it all quite figured out.

So anyway, whilst a 'blackhole' or neutron star does not create a point of infinite gravity, it creates a very large space time curvature that could be described as a hole. Since it emits no light, it is black.

Fourth dimensional geometry aside, it is just a very round rather small heavy object.

So, I still think that the hole comes from the notion of space time curvature, not the fact that is not actually a hole, because that would be stupid. Its like calling someones face an ass just because they talk shit.

When mass, photons, or anything is on the surface of a neutron star or 'black hole' it stays there until it is either ejected or removed by quantum mechanical effects. Maybe even hawking radiation.

But if we can't get at the information in any way, isn't it lost?That said, a lot of what you're complaining about feels more like semantics than actual issue with the theories involved, you need to sort that out first. You go from "There is no hole!" to "The hole I believe refers to..." within two sentences.

No, you see, in the whole blackholes are an infinite point of density thing, the information I think gets destroyed because there is no space for it. Information cannot be destroyed because that violates the conservation of energy principle.

Anyway just because information is not attainable, doesn't mean it doesn't exist. For example, if I wrote waterproof letter to someone and threw it in the ocean and its recipient doesn't get to read it, it doesn't mean the words on the paper disappear. They are still there, but not accessible at that time.

I was using the second word "hole" figurativley, maybe I should have used inverted commas or something.

No, you see, in the whole blackholes are an infinite point of density thing, the information I think gets destroyed because there is no space for it.

It's not considered infinitely dense - just sufficient that information/matter can't escape it's gravity at a certain distance. The problem isn't the information not having enough "space", it's that there's no conceivable way to get at it, ever again, once it crosses the event horizon.

Hum, well I know nothing about cars and I'll admit, no one knows anything about space really. But According to a little known Albert Einstein an object, if its an atom or a planet, maybe even a star bends space around it.

"Maybe"? Seriously?With all due respect, you sound like you haven't read anything on cosmology *since* Einstein.

"I'll admit, no one knows anything about space really" - c'mon, don't conflate what you know with what others have learned in the last 100 years.

You need to choose your words more carefully and make your points more succinctly. There are smart people here and it's an interesting subject (understatement!) but you need to show a little humility.

I think that Hawking has lost the only really function part of his body: his mind. Lately his theories have come from left field and so far out of his area of expertise that it makes me feel sorry for him.

I don't see how the mass at the centre of black holes can be infinite - if it was, then their gravitational fields would be also...

I think that the problem we have, is understanding just how and why gravity is not bound by the speed of light, which is why 'black-holes' can and do exist - the 'event horizon' is merely a barrier of both speed and efficiency which any objects of mass normally cannot break. The force of gravity, however, is efficient enough to do so.

No force we know of transfers energy as efficiently as gravity - NONE - which is why we're having problems, because we detect 'things' by their INefficiency - (which is what causes mass in the first place). Most of the problems we have with gravity is trying to make it fit within an inefficient system we know of - which should tell us we're not seeing the whole picture yet, at the right level.

But just because it can't be accessed in any conceivable way, doesn't mean it doesn't still exist.

If 'black holes' do evaporate eventually, then the information would be released.

I read something about this ages ago, it is a little confusing but it goes something like this....

Say if you and I were standing on 'the event horizon' (not the spaceship) and you pushed me in over the 'edge' the point of no return so to speak... I would fall to the surface of the point of matter and be crushed, but you would still see my image (probably of me saying "you bastard!") and there my image would remain for ever. So perhaps in a sense the information is represented on the event horizon.... I don't know, this is all starting to sound very holographic.... hahahha! 2D images representing things in 3D space.

I believe part of this 'hologram' theory was an answer to the information paradox, you guessed it, another theory not based on any actual facts. So that makes holographic theory a theory based on no facts based on a theory that is also completely speculative that belongs in the pure maths realm.

There is no distinction between "pure maths" and the concrete/real universe, certainly not since quantum mechanics spent the last 80 years or so by using pure maths to make (often counter-intuitive) predictions that were confirmed decades after, and with unbelievable precision, when experimental physics caught up and could validate the theory. That doesn't mean all theories turn out to be right; a proven math theorem is "right" forever, and a sound math theory cannot be wrong in itself, but it can be incomplete or insufficient to draw conclusions about what it models... physicists usually have a firm idea of which theories are complete enough so they can be added to the canon even before their predictions can be tested.

Like it or not, the map IS the territory in modern physics. It's nonsense talking about the "real world" as if there was any way, other than maths, to define it. Observation is certainly not that way, because we're discussing about stuff that long exceeded our ability to directly observe - from Planck scales to big bang stories - even the observable evidence from particle accelerators is highly filtered by interpretation, it's by definition impossible to directly observe fundamental particles that collide and the rubble they produce.

The guy who thought of it.... (I forgot his name) Or purposefully repressed it because he is such an ass!!

So first off, this is not science, it is wild speculative nonsense.

Also, what is all the mystery surrounding black holes?

I believe part of this 'hologram' theory was an answer to the information paradox, you guessed it, another theory not based on any actual facts. So that makes holographic theory a theory based on no facts based on a theory that is also completely speculative that belongs in the pure maths realm.

I don't know how this crap is allowed air time. I actually saw the guy say " I walked passed a hologram one time and thought, I wonder if the universe is like that" ... then went to his desk, made some silly equation up then comes across as the most unbelievable asshole talking assertively that "you can't understand this theory because I don't even understand it" ..... You know what? Why don't you just go work at burger king, because you and the staff there would be on the same level.

Please refrain from posting: you appear to have no clue how theoretical/mathematical physics research is conducted and why merely speculating how the universe could function from a purely "mathematical" standpoint could possibly be of value.

Further, Gerard 't Hooft, the Nobel laureate you insult, is far from an asshole and a moron.

Consider describing the state of a room with a fixed size by describing the state of the constituent parts. Heisenberg's uncertainty principle (Quantum Mechanics) states that the smaller the size of constituents (atoms, neutrons, quarks, ...) you use (the width of the elements in the field) the more energy you need.

E=mc^2 (Gravity) states that energy has mass. When mass reaches a certain size you end up with a black hole. This implies there is a limit to the smallest constituents you can cram into the room and thus the amount of information needed to describe the room.

In a black hole, the more energy/mass you add to it the larger its radius becomes (R=GM). The black hole's surface area is related to the amount of entropy (Thermodynamics) it has -- S=A/l^2. This is backed up by black holes having temperature (Hawking).

This means that you can describe the state of the black hole by just the information/entropy on its surface. You can convert the room to a black hole with the same surface area as the room, so you can describe the state of the room by the amount of information on its surface area.

Look man, your conception of physics is Newtonian. Perhaps pre-Newtonian. I know you think you understand what a black hole is, but you don't; it's obvious when you say crap like "surface of a neutron star or 'black hole'", as if those are two things that are just like each other.

There's no doubt that there's something interesting (and "interesting" is the most interesting word in science!) going on here. It IS a big deal, and the answer ISN'T obvious. You're like an alchemist mocking the holes in Mendeleev's periodic table.

And another thing, Hawking isn't considered a genius because he's never wrong; geniuses are often wrong. Newton believed in alchemy (hey, you're not in bad company!), Galileo didn't believe the moon controlled the tides (aside: Bill O'Reily doesn't get a pass; he's still an idiot), Einstein didn't believe that quantum mechanics could possibly be right. Hawking is a genius because when it comes to hard questions--like this one--he can perform the work to find an answer. Because of that, and all the practice he has doing it, his intuition is often right. But not always, and in this case he, and a lot of other geniuses, have their intuitions pointing in different directions. Now, they're all going to go do that hard work they do which earned them the title "genius", and hopefully, they'll find an answer.

Please refrain from posting: you appear to have no clue how theoretical/mathematical physics research is conducted and why merely speculating how the universe could function from a purely "mathematical" standpoint could possibly be of value.

Further, Gerard 't Hooft, the Nobel laureate you insult, is far from an asshole and a moron.

All theories some more concrete than others start out as speculation, the ones that are proven to be correct provide us with some really great stuff, like computers and all sorts of clever things. Also mathematics is very important, even pure maths, because some number sets and 'imaginary numbers' are used for practical application, like i dunno, Radar.

Obviously I don't have some sort of hatred towards the people who can take a theory and apply the maths to it to come out with something logical and interesting.

Mr 't hooft as won a freaking nobel prize in physics, so I am not trying to say "I know more than him" I just think that sometimes people start going a little crazy when they are trying to understand things that can fundamentally never be fully understood. Its still great to try, as it eventually leads to interesting discoveries and it gives them something to live for.

Lets face it, there will be hundreds more theories than this, there are plenty of others, each new discovery will lead to more questions than it answered, not every one can be right. Mr 't hooft may have provided the physics world with invaluable research, as has Bhor, Einstein, Heisenberg, Planck, etc they are all great people but none of them have ever formed a complete description of reality. Lets just say I didn't care for 't hooft's elitist tone when I heard him. From what I have read and know, (or don't know) about quantum theory and gravity is that there is a fundamental problem with how the two work together in current mathematical descriptions. Ok, I would love to hear holographic theory explain gravity.

I think its back to the drawing board on this one.... and yes, that is just my humble opinion, and since I don't live in Iran, I'm entitled to it!!

In brushing up on my physics recently, I came to the realization for the first time that time dilation as you approach the speed of light directly implies that anything moving at the speed of light experiences fewer spatial dimensions in its reference frame, since the spatial dimension in the direction of travel contracts to 0 length at the speed of light. Recently I also read that someone (Roger Penrose I believe, but can't find the reference right now) has recently proposed (as best I can recall) that the universe might have had fewer spatial dimensions early in the life of the universe, since before the Higgs mechanism gave mass to particles, all particles were massless, and thus moved the speed of light, and thus experienced only 2 dimensions.

I've been wondering whether this loss of a spatial dimension at the speed of light is related to the holographic conjecture, since they both seem to imply the same sort of reduction to 2 spatial dimensions. It would make sense to me, since my (probably not quite right) intuition about how things "appear" to enter black holes is that they accelerate towards the black hole with the increasing velocity relativistically flattening the dimension of travel for the particles until they are all smashed flat in a permanent 2-dimensional "image" of the infalling objects on the event horizon.

Anybody know if there is supposed to be a connection between these two things?

Like most of the String Theory, this too is complete nonsense and junk science. It's completely unfalsifiable and "not even wrong" as Fermi used to say.

String theory = religion.

String theory isn't the topic of the article at all. Even though the phrase is used twice, it's used once as contrast (string theory: add several dimensions; holographic theory: subtract one) and once to call out a shared problem, which is the same problem "you brought" to the discussion, that of "but is the math reflected in the real world?" Which is why, you know, it's being tested... http://science.slashdot.org/story/10/10 ... rse-Theory

I find it interesting that t'Hooft sees a way for this to inject a more causal nature into our understanding of quantum theory. The probablistic thing has always bothered me, and it took me quite a while and quite a bit of reading (thanks to the Arsians who pointed me in the right directions) to finally find thatprobablism hadn't, in fact, been shown to be factual. Not being a physicist, I've been sitting back, reading, and waiting for either Bell's theorem to be proven or for someone to find those pesky hidden variables.

That t'Hooft himself sees an opening for it gives me a bit of hope, and I feel less like a heretic when I say Einstein had it right.